Dithering

# minimized average error
y_dim = self.img_dims[0]
            x_dim = self.img_dims[1]

            rgb_coded = np.zeros_like(self.rgb)
            self.color_table_indices = np.zeros((self.rgb.shape[0]), dtype=np.uint8)

            for i in range(rgb_coded.shape[0]):
                self.color_table_indices[i] = self.find_nearest_color(self.rgb[i, :])
                rgb_coded[i, :] = self.color_table[self.color_table_indices[i]]

                quant_error = self.rgb[i, :] - rgb_coded[i, :]

                if (i + 1 < self.rgb.shape[0] and ((i + 1) % x_dim) != 0):
                    self.rgb[i + 1, :] += ((7 / 48) * (quant_error)).astype(np.uint16)
                if (i + 2 < self.rgb.shape[0] and ((i + 2) % x_dim) != 0):
                    self.rgb[i + 2, :] += ((5 / 48) * (quant_error)).astype(np.uint16)
                if (i + x_dim - 2 < self.rgb.shape[0] and ((i - 1) % x_dim) != 0):
                    self.rgb[i + x_dim - 2, :] += ((3 / 48) * (quant_error)).astype(np.uint16)
                if (i + x_dim - 1 < self.rgb.shape[0] and ((i) % x_dim) != 0):
                    self.rgb[i + x_dim - 1, :] += ((5 / 48) * (quant_error)).astype(np.uint16)
                if (i + x_dim < self.rgb.shape[0]):
                    self.rgb[i + x_dim, :] += ((7 / 48) * (quant_error)).astype(np.uint16)
                if (i + x_dim + 1 < self.rgb.shape[0] and ((i + 1) % x_dim) != 0):
                    self.rgb[i + x_dim + 1, :] += ((5 / 48) * (quant_error)).astype(np.uint16)
                if (i + x_dim + 2 < self.rgb.shape[0] and ((i + 2) % x_dim) != 0):
                    self.rgb[i + x_dim + 2, :] += ((3 / 48) * (quant_error)).astype(np.uint16)
                if (i + 2*x_dim - 2 < self.rgb.shape[0] and ((i - 1) % x_dim) != 0):
                    self.rgb[i + 2*x_dim - 2, :] += ((1 / 48) * (quant_error)).astype(np.uint16)
                if (i + 2*x_dim - 1 < self.rgb.shape[0] and ((i) % x_dim) != 0):
                    self.rgb[i + 2*x_dim - 1, :] += ((3 / 48) * (quant_error)).astype(np.uint16)
                if (i + 2*x_dim < self.rgb.shape[0]):
                    self.rgb[i + 2*x_dim, :] += ((5 / 48) * (quant_error)).astype(np.uint16)
                if (i + 2*x_dim + 1 < self.rgb.shape[0] and ((i + 1) % x_dim) != 0):
                    self.rgb[i + 2*x_dim + 1, :] += ((3 / 48) * (quant_error)).astype(np.uint16)
                if (i + 2*x_dim + 2 < self.rgb.shape[0] and ((i + 2) % x_dim) != 0):
                    self.rgb[i + 2*x_dim + 2, :] += ((1 / 48) * (quant_error)).astype(np.uint16)

            self.img_coded = rgb_coded.reshape((self.img_dims[0], self.img_dims[1], 3))